U.S. patent application number 17/440390 was filed with the patent office on 2022-03-24 for high stiff thermoplastic compositions for thin-wall structures.
The applicant listed for this patent is SHPP GLOBAL TECHNOLOGIES B.V.. Invention is credited to Eddie Kebin GENG, Edward KUNG, Adam STARRY.
Application Number | 20220089860 17/440390 |
Document ID | / |
Family ID | 1000006028613 |
Filed Date | 2022-03-24 |
United States Patent
Application |
20220089860 |
Kind Code |
A1 |
GENG; Eddie Kebin ; et
al. |
March 24, 2022 |
HIGH STIFF THERMOPLASTIC COMPOSITIONS FOR THIN-WALL STRUCTURES
Abstract
A thermoplastic composition includes: from about 29 wt % to
about 49 wt % of a thermoplastic polymer component including a
first thermoplastic polymer consisting of polybutylene
terephthalate and a second thermoplastic polymer consisting of
polycarbonate, polyethylene terephthalate, copolymers thereof, or a
combination thereof; from about 1 wt % to about 30 wt % of a
component comprising a polyester elastomer, an ethylene/alkyl
acrylate/glycidyl methacrylate terpolymer compatibilizer, or a
combination thereof; and from about 50 wt % to about 70 wt % of a
ceramic fiber component including ceramic fibers. The first
thermoplastic polymer is present the composition in a ratio of at
least 2:1 as compared to the second thermoplastic polymer. Articles
including the thermoplastic composition are also described.
Inventors: |
GENG; Eddie Kebin; (Exton,
PA) ; STARRY; Adam; (Exton, PA) ; KUNG;
Edward; (Selkirk, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHPP GLOBAL TECHNOLOGIES B.V. |
Bergen op Zoom |
|
NL |
|
|
Family ID: |
1000006028613 |
Appl. No.: |
17/440390 |
Filed: |
March 20, 2020 |
PCT Filed: |
March 20, 2020 |
PCT NO: |
PCT/IB2020/052628 |
371 Date: |
September 17, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 67/02 20130101;
C08L 2205/03 20130101 |
International
Class: |
C08L 67/02 20060101
C08L067/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 21, 2019 |
EP |
19164387.3 |
Claims
1. A thermoplastic composition comprising: a. from about 29 wt % to
about 49 wt % of a thermoplastic polymer component comprising i. a
first thermoplastic polymer consisting of polybutylene
terephthalate, and ii. a second thermoplastic polymer consisting of
polycarbonate, polyethylene terephthalate, copolymers thereof, or a
combination thereof, wherein the first thermoplastic polymer is
present the composition in a ratio of at least 2:1 as compared to
the second thermoplastic polymer; b. from about 1 wt % to about 30
wt % of a component comprising a polyester elastomer, an
ethylene/alkyl acrylate/glycidyl methacrylate terpolymer
compatibilizer, or a combination thereof; and c. from about 50 wt %
to about 70 wt % of a ceramic fiber component comprising ceramic
fibers, wherein the combined weight percent value of all components
does not exceed 100 wt %, and all weight percent values are based
on the total weight of the composition.
2. The composition according to claim 1, wherein the second
thermoplastic polymer comprises polycarbonate and a polycarbonate
copolymer, wherein the polycarbonate is a homopolymer comprising
repeating units derived from bisphenol A, and wherein the
polycarbonate copolymer comprises repeating units derived from
bisphenol A, sebacic acid, polysiloxane, isophthalate terephthalate
resorcinol (ITR), phosphate or a combination thereof.
3. The composition according to claim 2, wherein the polycarbonate
copolymer comprises a polycarbonate-polysiloxane copolymer having a
siloxane content of from about 5 wt % to about 45 wt % based on the
total weight of the polycarbonate-polysiloxane copolymer.
4. The composition according to claim 1, wherein the polycarbonate
is a polycarbonate copolymer including repeating units derived from
bisphenol A, sebacic acid, polysiloxane, isophthalate terephthalate
resorcinol (ITR), phosphate, or a combination thereof.
5. The composition according to claim 1, wherein the ceramic fibers
have a tensile modulus of at least 150 GPa and comprise chopped
ceramic fibers having a length of from about 0.1 millimeter (mm) to
about 1 mm in the composition.
6. The composition according to claim 1, wherein the composition
has a tensile modulus of at least 27 GPa as determined in
accordance with ASTM D638 or a notched Izod impact strength greater
than 280 J/m at 23.degree. C. as determined in accordance with ASTM
D256.
7. The composition according to claim 1, wherein the ceramic fibers
comprise an alpha-crystalline alumina.
8. The composition according to claim 1, further comprising a
crystallization suppressant in an amount of from greater than 0 wt
% to about 10 wt % or a transesterification quenching agent in an
amount of from greater than 0 wt % to about 1 wt %.
9. The composition according to claim 1, further comprising an
additive material, the additive material selected from the group
consisting of: an antioxidant; a colorant; a de-molding agent; a
dye; a flow promoter; a flow modifier; a light stabilizer; a
lubricant; a mold release agent; a pigment; a quenching agent; a
thermal stabilizer; an ultraviolet (UV) absorbant; a UV reflectant;
a UV stabilizer; an epoxy chain extender; a flame retardant; and a
combination thereof.
10. The composition according to claim 1, wherein a molded sample
of the thermoplastic composition has a tensile modulus of at least
about 25 gigapascals (GPa) as determined in accordance with ASTM
D638 or a molded sample of the thermoplastic composition has a
flexural modulus of at least about 15 GPa as determined in
accordance with ASTM D638.
11. The composition according to claim 1, wherein the thermoplastic
composition is chemically resistant.
12. An article comprising a composition according to claim 1,
wherein the article comprises a thin wall having a nominal
thickness of less than about 2 mm.
13. The article according to claim 12, wherein the article has a
shear viscosity at 150 cp of less than about 2500 s-1 as determined
in accordance with ASTM D3835.
14. The article according to claim 12, wherein the article is
extrusion-molded, injection-molded, compression-molded,
thermoformed, overmolded, or insert-molded with a metallic or
composite laminate insert.
15. The article according to claim 12, wherein the article is
selected from the group consisting of: a communication device; a
computer device; an electromagnetic interference device; a printed
circuit; a Wi-Fi device; a Bluetooth device; a GPS device; a
cellular antenna device; a smart phone device; a wireless
communication device; a structured media enclosure; an antenna
concealing enclosure; an enclosure for networking equipment; a
structural component of an electronic device; a portable computing
device; a hand-held electronic device; an automotive device; a
medical device; a sensor device; a security device; a shielding
device; an RF antenna device; an LED device; and an RFID device.
Description
FIELD OF THE DISCLOSURE
[0001] The present disclosure relates to thermoplastic compositions
including a ceramic fiber component, and more particularly to
thermoplastic compositions including a ceramic fiber component, a
polybutylene terephthalate component, and a thermoplastic polymer
component including polycarbonate and/or polyethylene
terephthalate.
BACKGROUND
[0002] Many consumer-oriented industries, e.g., the consumer
electronics industry, have a need for blended thermoplastic
compositions that provide very high stiffness with balanced
ductility and impact resistance, are colorable from white to black,
chemically resistant to everyday chemicals, possess excellent flow
for thin wall processing, and transparency to wireless signals.
Blends including polycarbonate (PC) and polybutylene terephthalate
(PBT) with glass fibers can meet the above requirements to some
extent, as described in U.S. Pat. No. 9,284,449. Compositions
including high flow crystalline resins such as polyether ether
ketone polymers (PEEK) or specialty nylon with glass fibers have
also been used. Materials containing PEEK desirably have low
dielectric interference to wireless signals, but the glass fibers
in these compositions have a low stiffness, relatively poor
dimensional stability and thus limit the stiffness of compositions
incorporating them. In addition, parts including glass fibers--and
in particular thin-wall molded parts--generally have higher
warpage. Glass fibers are thus not typically used in applications
requiring mechanically demanding parts. Fillers with a higher
stiffness, such as carbon fibers, have the potential to improve the
stiffness of thermoplastic compounds incorporating them, but they
interfere with radio/wireless transmissions. In addition,
conventional carbon fibers are not colorable.
[0003] These and other shortcomings are addressed by aspects of the
present disclosure.
SUMMARY
[0004] Aspects of the present disclosure address the stiffness
limitations of glass fiber-filled thermoplastic compounds in
mechanically demanding consumer electronics parts applications, and
provide a solution that exhibits a combination of one or more of
the properties of high stiffness, high tensile elongation at break,
good impact resistance, good colorability, and excellent chemical
resistance.
[0005] Particular aspects of the disclosure relate to thermoplastic
compositions including: (a) from about 29 wt % to about 49 wt % of
a thermoplastic polymer component including a first thermoplastic
polymer consisting of polybutylene terephthalate, and a second
thermoplastic polymer consisting of polycarbonate, polyethylene
terephthalate, copolymers thereof, or a combination thereof; (b)
from about 1 wt % to about 30 wt % of a component comprising a
polyester elastomer, an ethylene/alkyl acrylate/glycidyl
methacrylate terpolymer compatibilizer, or a combination thereof;
and (c) from about 50 wt % to about 70 wt % of a ceramic fiber
component comprising ceramic fibers. The first thermoplastic
polymer is present the composition in a ratio of at least 2:1 as
compared to the second thermoplastic polymer, the combined weight
percent value of all components does not exceed 100 wt %, and all
weight percent values are based on the total weight of the
composition.
[0006] Articles formed from the thermoplastic compositions and
methods of forming the articles are also described.
BRIEF DESCRIPTION OF THE FIGURES
[0007] In the drawings, which are not necessarily drawn to scale,
like numerals may describe similar components in different views.
Like numerals having different letter suffixes may represent
different instances of similar components. The drawings illustrate
generally, by way of example, but not by way of limitation, various
embodiments discussed in the present document.
[0008] FIG. 1 is a graph showing shear viscosity for several
compositions described herein.
[0009] FIG. 2 is another graph showing shear viscosity for several
compositions described herein.
[0010] FIG. 3 is an additional graph showing shear viscosity for
several compositions described herein.
DETAILED DESCRIPTION
[0011] The present disclosure can be understood more readily by
reference to the following detailed description of the disclosure
and the Examples included therein. In various aspects, the present
disclosure pertains to thermoplastic compositions including: (a)
from about 29 wt % to about 49 wt % of a thermoplastic polymer
component including a first thermoplastic polymer consisting of
polybutylene terephthalate, and a second thermoplastic polymer
consisting of polycarbonate, polyethylene terephthalate, copolymers
thereof, or a combination thereof, wherein the first thermoplastic
polymer is present the composition in a ratio of at least 2:1 as
compared to the second thermoplastic polymer; (b) from about 1 wt %
to about 30 wt % of a component comprising a polyester elastomer,
an ethylene/alkyl acrylate/glycidyl methacrylate terpolymer
compatibilizer, or a combination thereof; and (c) from about 50 wt
% to about 70 wt % of a ceramic fiber component including ceramic
fibers. The combined weight percent value of all components does
not exceed 100 wt %, and all weight percent values are based on the
total weight of the composition. Articles formed from the
thermoplastic compositions and methods of forming the articles are
also described.
[0012] Before the present compounds, compositions, articles,
systems, devices, and/or methods are disclosed and described, it is
to be understood that they are not limited to specific synthetic
methods unless otherwise specified, or to particular reagents
unless otherwise specified, as such can, of course, vary. It is
also to be understood that the terminology used herein is for the
purpose of describing particular aspects only and is not intended
to be limiting.
[0013] Various combinations of elements of this disclosure are
encompassed by this disclosure, e.g., combinations of elements from
dependent claims that depend upon the same independent claim.
[0014] Moreover, it is to be understood that unless otherwise
expressly stated, it is in no way intended that any method set
forth herein be construed as requiring that its steps be performed
in a specific order. Accordingly, where a method claim does not
actually recite an order to be followed by its steps or it is not
otherwise specifically stated in the claims or descriptions that
the steps are to be limited to a specific order, it is no way
intended that an order be inferred, in any respect. This holds for
any possible non-express basis for interpretation, including:
matters of logic with respect to arrangement of steps or
operational flow; plain meaning derived from grammatical
organization or punctuation; and the number or type of embodiments
described in the specification.
[0015] All publications mentioned herein are incorporated herein by
reference to disclose and describe the methods and/or materials in
connection with which the publications are cited.
[0016] High filler loading causes poor flow properties, which in
turn can reduce the melt processability of the composition. The low
melt flow specifically reduces the thin wall molding ability. There
is a need in the art for polymer composites that provide thin wall
moldability and have good flow, mold release performance,
ductility, and Izod impact strength properties. Disclosed in
various aspects herein are thin walled, moldable, thermoplastic
compositions having improved flow, ductility, and impact
strength.
[0017] In various aspects, the disclosure relates to articles
comprising compositions disclosed herein. For example, the
disclosed composition relates to thin walled articles comprising
the disclosed composition. In this regard, a thin wall is a section
of a product that is more narrow when compared to its length and
width. As disclosed herein, a thin wall can have a nominal
thickness of less than about 3 mm, or in certain aspects less than
about 2 mm or less than about 1 mm. The thin walled article can be
processed for use in an array of fields, for example, as a housing
for a consumer electronic device.
[0018] In a further aspect, the present disclosure pertains to
methods of preparing thin walled, moldable thermoplastic
compositions.
Thermoplastic Compositions
[0019] Aspects of the disclosure relate to a thermoplastic
composition including:
[0020] a. from about 29 wt % to about 49 wt % of a thermoplastic
polymer component including [0021] i. a first thermoplastic polymer
consisting of polybutylene terephthalate, and [0022] ii. a second
thermoplastic polymer consisting of polycarbonate, polyethylene
terephthalate, copolymers thereof, or a combination thereof, [0023]
wherein the first thermoplastic polymer is present the composition
in a ratio of at least 2:1 as compared to the second thermoplastic
polymer;
[0024] b. from about 1 wt % to about 30 wt % of a component
comprising a polyester elastomer, an ethylene/alkyl
acrylate/glycidyl methacrylate terpolymer compatibilizer, or a
combination thereof; and
[0025] c. from about 50 wt % to about 70 wt % of a ceramic fiber
component including ceramic fibers. The combined weight percent
value of all components does not exceed 100 wt %, and all weight
percent values are based on the total weight of the
composition.
[0026] The thermoplastic polymer component includes a first
thermoplastic polymer including polybutylene terephthalate (PBT),
and a second thermoplastic polymer including polycarbonate,
polyethylene terephthalate, copolymers thereof, or a combination
thereof.
[0027] As used herein, polybutylene terephthalate can be used
interchangeably with poly(1,4-butylene terephthalate). PBT is a
type of polyester. The polybutylene terephthalate may include a
chemically-upcycled PBT, such as the VALOX.TM. resins available
from SABIC.
[0028] In certain aspects the PBT is an up-cycled polymer derived
from SABIC's iQ process. In such a process, polyethylene
terephthalate (PET) is depolymerized to monomers such as the
terephthalate-containing monomer bis(2-hydroxyethyl) terephthalate
(BHET) and ethylene glycol (EG). Subsequently, the BHET is
polymerized with butane diol (BDO) to form the PBT. In a particular
aspect, PET is combined with ethylene glycol (EG) in a
depolymerization reactor operating at, e.g., 230 degrees Celsius
(.degree. C.) and a pressure of 3.5 bar. The resulting oligomer
product includes BHET, EG and PET monomers. This product is
combined with BDO in a transesterification reactor operating at,
e.g., 230-245.degree. C. and under a 500 millibar (mbar) vacuum to
form a trans-esterified PBT oligomer product; EG is distilled out
during transesterification. The trans-esterified PBT oligomer
product is then polymerized in a polymerization reactor operating
at, e.g., <1 mbar to form the PBT.
[0029] As used herein, polycarbonate refers to an oligomer or
polymer including residues of one or more dihydroxy compounds,
e.g., dihydroxy aromatic compounds, joined by carbonate linkages;
it also encompasses homopolycarbonates, copolycarbonates, and
(co)polyester carbonates. In certain aspects, the polycarbonate can
include any polycarbonate material or mixture of materials, for
example, as recited in U.S. Pat. No. 7,786,246, which is hereby
incorporated in its entirety for the specific purpose of disclosing
various polycarbonate compositions and methods. In some aspects the
polycarbonate is a homopolymer including repeating units derived
from bisphenol A. The polycarbonate may include polycarbonate
monomers such as, but not limited to, 2-phenyl-3,3'-bis (4-hydroxy
phenyl) phthalimidine (PPPBP) and dimethyl bisphenol cyclohexane
(DMBPC).
[0030] In particular aspects the second thermoplastic polymer
includes a polycarbonate copolymer including repeating units
derived from bisphenol A, sebacic acid, polysiloxane, isophthalate
terephthalate resorcinol (ITR), phosphate or a combination thereof.
Exemplary polycarbonate copolymers include, but are not limited to,
polycarbonate-siloxane copolymers (such as EXL resin available from
SABIC), isophthaloyl and terephthaloyl resorcinol (ITR)
polyester-carbonate (such as SLX resin available from SABIC), high
flow high heat polycarbonate copolymer (such as XHT resin available
from SABIC), high flow ductile polycarbonate copolymers (such as
LEXAN.TM. HFD available from SABIC), oligomeric phosphonate (such
as FRX resin available from FRX Polymers, Inc.). The polycarbonate
may be end-capped and may include, but is not limited to, the
following endcapping agents: 1,1',1'',-tris (4'-hydroxyphenyl)
ethane (THPE) and p-hydroxybenzonitrile (HBN). In particular,
HBN-endcapped polycarbonate (such as CFR polycarbonate resin
available from SABIC) could contribute to flame retardancy (FR)
performance of the thermoplastic compositions. The polycarbonate
and/or the polycarbonate copolymer may include or be derived from a
post-consumer recycle polycarbonate.
[0031] In certain aspects the second thermoplastic polymer includes
a polycarbonate-siloxane copolymer. The polycarbonate-siloxane
copolymer in some aspects has a siloxane content of from about 5 wt
% to about 45 wt % based on the total weight of the
polycarbonate-polysiloxane copolymer. In further aspects the
polycarbonate-siloxane copolymer has a siloxane content of from
about 20 wt % to about 45 wt % based on the total weight of the
polycarbonate-polysiloxane copolymer. In specific aspects the
polycarbonate-siloxane copolymer has a siloxane content of about 40
wt % based on the total weight of the polycarbonate-polysiloxane
copolymer.
[0032] As used herein, polyethylene terephthalate (PET) can be used
interchangeably with poly(ethyl benzene-1,4-dicarboxylate). As with
polybutylene terephthalate, polyethylene terephthalate is a type of
polyester.
[0033] In some aspects the first thermoplastic polymer is present
the composition in a ratio of at least 2:1 as compared to the
second thermoplastic polymer. In further aspects the first
thermoplastic polymer is present the composition in a ratio of at
least 3:1 as compared to the second thermoplastic polymer. In yet
further aspects the first thermoplastic polymer is present the
composition in a ratio of at least 4:1 as compared to the second
thermoplastic polymer. It has been found that thermoplastic
compositions having a ratio of PBT (i.e., first thermoplastic
polymer) to polycarbonate (i.e., second thermoplastic polymer) of
at least 2:1, or in particular aspects a ratio of 3:1 or 4:1, have
good chemical resistance to agents that have been known to degrade
thermoplastic polymers. One such agent is Banana Boat.RTM.
sunscreen.
[0034] The thermoplastic composition may include from about 1 wt %
to about 30 wt % of a component comprising a polyester elastomer,
an ethylene/alkyl acrylate/glycidyl methacrylate terpolymer
compatibilizer, or a combination thereof. This component may
function as an impact modifier to enhance the mechanical properties
(e.g., impact strength) of the composition.
[0035] The polyester elastomer component may include, but is not
limited to, polybutylene tere/isophthalate-co-polyoxybutylene. In a
particular aspect the polyester elastomer component includes
Hytrel.RTM. 4056, available from DuPont. In a further aspect the
polyester elastomer component includes Arnitel.RTM. thermoplastic
copolyester (TPC), available from DSM.
[0036] The ethylene/alkyl acrylate/glycidyl methacrylate terpolymer
compatibilizer component may include, but is not limited to,
ethylene methyl acrylate glycidyl methacrylate, ethylene ethyl
acrylate glycidyl methacrylate, and combinations thereof. In a
particular aspect the ethylene/alkyl acrylate/glycidyl methacrylate
terpolymer compatibilizer component is a PC/terpolymer blend, such
as Lotader.RTM. AX8900, available from Arkema. In certain aspects
in which the thermoplastic polymer component includes polyethylene
terephthalate and not polycarbonate, it may be possible to omit the
ethylene/alkyl acrylate/glycidyl methacrylate terpolymer
compatibilizer component from the thermoplastic composition. In
such aspects the ethylene/alkyl acrylate/glycidyl methacrylate
terpolymer compatibilizer component may be present in the
thermoplastic composition in a range of from 0 wt % to about 10 wt
%.
[0037] The composition may further include an acrylic impact
modifier component. The acrylic impact modifier may include, but is
not limited to, an ethylene-ethyl acrylate copolymer. In a
particular aspect the acrylic impact modifier component
Elvaloy.RTM. AC 2615, available from DuPont, which is an
ethylene-ethyl acrylate copolymer having an ethyl acrylate content
below 20%.
[0038] The thermoplastic composition includes from about 50 wt % to
about 70 wt % of a ceramic fiber component. The ceramic fiber
component can include any suitable type of ceramic fiber. In
certain aspects the ceramic fiber includes, but is not limited to,
alumina, polycrystalline alumina, alpha-crystalline alumina,
aluminum silicate, and combinations thereof.
[0039] In a particular aspect the ceramic fiber component includes
a chopped ceramic fiber such as Nextel.TM. 610, a ceramic oxide
fiber available from 3M in raw form having a fiber length of 3-6
millimeter (mm). When incorporated into the thermoplastic
composition in typical compounding processes (e.g., a twin-screw
extrusion compounding process), the final fiber length of this
fiber is from about 0.1 mm to about 1 mm in the composition. In
certain aspects the ceramic fiber component includes a chopped
ceramic fiber such as, but not limited to, Nextel.TM. 312,
Nextel.TM. 440, Nextel.TM. 720, or a combination thereof. The
ceramic fibers may be nonmagnetic and/or non-electrically
conductive in some aspects.
[0040] The ceramic fiber may in some aspects have a tensile modulus
of at least about 150 gigapascals (GPa). In further aspects the
ceramic fiber has a tensile modulus of from about 150 GPa to about
500 GPa, or from about 150 GPa to about 300 GPa.
[0041] The ceramic fiber component may be a continuous laminate, a
unidirectional tape, or prepeg in certain aspects.
[0042] In some aspects the thermoplastic composition includes a
crystallization suppressant in an amount of from greater than 0 wt
% to about 10 wt %. The crystallization suppressant, when included,
may function to reduce the PBT crystallization rate so that the
thermoplastic polymer component can retain a molten state for a
longer period of time, allowing the mold to fill without
solidifying too quickly. It can also produce molded parts having a
smoother and glossier surface. This smooth and glossy surface may
be desired in certain applications in which a high surface quality
promotes good adhesion to a substrate (for example, a metal insert
surface). Exemplary crystallization suppressants include, but are
not limited to, SLX copolymer or polyetherimide (e.g. ULTEM.TM.
resin, available from SABIC).
[0043] The thermoplastic composition may in some aspects include a
transesterification quenching agent in an amount of from greater
than 0 wt % to about 1 wt %. The transesterification quenching
agent may be included as a processing aid and could help prevent a
transesterification reaction between polycarbonate and PBT (when PC
is included in the thermoplastic polymer component). The
transesterification quenching agent may be omitted in some aspects
where the thermoplastic polymer component includes PET. In a
further aspect, the transesterification quenching agent includes a
phosphorus-containing stabilizer. In a yet further aspect, the
transesterification quenching agent includes an acidic phosphate
salt, e.g. a monozinc phosphate, sodium dihydrogen phosphate,
potassium hydrogen phosphate, calcium hydrogen phosphate, sodium
acid pyrophosphate and mixtures thereof. In an even further aspect,
the transesterification quenching agent includes a phosphite
compounds, e.g., a phosphite compound of the general formula
P--(OR').sub.3 wherein each R' is the same or different and
independently represents hydrogen, alkyl groups, aryl groups or any
mixture thereof provided that at least one of the R' groups is
hydrogen or alkyl. Illustratively, these include, but are not
limited to, diphenylisodecyl phosphite, diisooctyl phosphite,
dilauryl phosphite, diphenyl phosphite, phenyl diisodecyl
phosphite, ethyl hexyl diphenyl phosphite, stearyl phosphite and
mixtures thereof. In a still further aspect, the
transesterification quenching agent comprises a Group IB or Group
IIB phosphate salt such as zinc phosphate. In a further aspect, the
transesterification quenching agent includes a phosphorous oxo-acid
such as phosphorous acid, phosphoric acid, polyphosphoric acid, or
hypophosphorous acid.
[0044] In a further aspect, the phosphorus-containing stabilizer is
selected from zinc phosphate, diphenylisodecyl phosphite,
monosodium phosphate and sodium acid pyrophosphate and mixtures
thereof. In a still further aspect, the phosphorus-containing
stabilizer is zinc phosphate.
[0045] In a further aspect, the transesterification quenching agent
is selected from an acidic phosphate salt, a Group IB phosphate
salt, a Group IIB phosphate salt, a phosphorus oxo-acid, and
mixtures thereof. In a still further aspect, the
transesterification quenching agent is an acidic phosphate salt. In
a yet further aspect, the transesterification quenching agent is
selected from a Group IB phosphate salt and a Group IIB phosphate
salt. In an even further aspect, the transesterification quenching
agent is mono zinc phosphate. In a still further aspect, the
transesterification quenching agent is a phosphorus oxo-acid. The
transesterification quenching agent can be sodium stearate. In
particular aspects the transesterification quenching agent may
include, but is not limited to, an acidic phosphate salt, a Group
IB phosphate salt, a Group IIB phosphate salt, a phosphorus
oxo-acid, and combinations thereof.
[0046] In addition to the foregoing components, the disclosed
thermoplastic compositions can optionally include a balance amount
of one or more additive materials ordinarily incorporated in
thermoplastic compositions of this type, with the proviso that the
additives are selected so as to not significantly adversely affect
the desired properties of the thermoplastic composition.
Combinations of additives can be used. Such additives can be mixed
at a suitable time during the mixing of the components for forming
the composition. Exemplary and non-limiting examples of additive
materials that can be present in the disclosed thermoplastic
compositions include an antioxidant, a colorant, a de-molding
agent, a dye, a flow promoter, a flow modifier, a light stabilizer,
a lubricant, a mold release agent, a pigment, a quenching agent, a
thermal stabilizer, a UV absorbant, a UV reflectant, a UV
stabilizer, an epoxy chain extender, and combinations thereof.
[0047] In particular aspects, an epoxy chain extender additive may
be included in the thermoplastic composition to counteract the
basicity of the ceramic fiber and/or to help improve/increase
long-term mechanical strength retention of the composition.
Exemplary epoxy chain extender additives may include, but are not
limited to, diglycidil ether and one or more of the JONCRYL.RTM.
products available from BASF Corp.
[0048] In some aspects a molded sample of the thermoplastic
composition has a tensile modulus of at least about 25 gigapascals
(GPa) as determined in accordance with ASTM D638, or a tensile
modulus of at least about 27 gigapascals (GPa) as determined in
accordance with ASTM D638. In further aspects a molded sample of
the thermoplastic composition has a tensile modulus of from about
15 GPa to about 200 GPa, or from about 20 GPa to about 150 GPa, or
from about 25 GPa to about 100 GPa.
[0049] In certain aspects a molded sample of the thermoplastic
composition has a tensile elongation at break of at least about
1.5% as determined in accordance with ASTM D638. In further aspects
a molded sample of the thermoplastic composition has a tensile
elongation at break of from about 1% to about 10%, or from about
1.5% to about 5%.
[0050] In particular aspects a molded sample of the thermoplastic
composition has a notched Izod impact strength of at least about
100 Joules per meter (J/m) as determined in accordance with ASTM
D256. In further aspects a molded sample of the thermoplastic
composition has a notched Izod impact strength of at least about
280 J/m as determined in accordance with ASTM D256. A molded sample
of the thermoplastic composition may in some aspects have a notched
Izod impact strength of from about 100 J/m to about 1000 J/m, or
from about 200 J/m to about 750 J/m, or from about 200 J/m to about
500 J/m, or from about 250 J/m to about 1000 J/m, or from about 280
J/m to about 500 J/m.
[0051] In some aspects a molded sample of the thermoplastic
composition has a shear viscosity at 150 cp of less than about 2500
s.sup.-1 as determined in accordance with ASTM D3835. In further
aspects a molded sample of the thermoplastic composition has a
shear viscosity at 150 cp of less than about 2000 s.sup.-1, or a
shear viscosity at 150 cp of less than about 1500 s.sup.-1.
[0052] Thermoplastic compositions according to aspects of the
disclosure may be chemically resistant, i.e., the mechanical
properties (including tensile modulus, tensile strength and/or
stiffness) and/or the visual appearance of the thermoplastic
composition are not negatively affected when exposed to common
chemicals that these thermoplastic compositions encounter. For
example, thermoplastic compositions according to the present
disclosure may be used in consumer electronics applications (e.g.,
a wireless communication device) and may be exposed to chemicals
such as, but not limited to: adhesives used to adhere the
composition (or an article including it) to other parts of the
electronics apparatus; sunscreen; and insect repellant. The
thermoplastic composition--and articles including them--could thus
be subject to chemical attack on external surfaces (e.g., sunscreen
and insect repellant) and internal surfaces (e.g., adhesives).
Thus, in certain aspects the thermoplastic compositions are
chemically resistant to adhesives, sunscreen, insect repellant or a
combination thereof. In one particular aspect, the thermoplastic
composition is chemically resistant to a heat-cured urethane
adhesive. In another particular aspect, the thermoplastic
composition is chemically resistant to a moisture-cured urethane
adhesive.
[0053] In further aspects thermoplastic compositions according to
aspects of the disclosure are chemically resistant to a change in
mechanical properties when exposed to adhesives, sunscreen and/or
insect repellant; i.e., a molded sample of the thermoplastic
composition retains at least 80% of its tensile
properties--including tensile modulus, tensile strength, and/or
stiffness--after exposure to adhesives, sunscreen and/or insect
repellant.
Articles of Manufacture
[0054] The thin-wall structure can be an injection molded compound
or a hybrid molded structure made with (1) a continuous fiber
fabric laminate or a UD tape structure, and (2) an injection molded
short fiber Compound/composite. The demonstrated characteristics of
the disclosed formulations make them well-suited for use in
articles of manufacture in the medical, electric and electronic
markets, especially those requiring thin-walled components.
[0055] In certain aspects, the present disclosure pertains to
shaped, formed, or molded articles including the thermoplastic
compositions. The thermoplastic compositions can be molded into
useful shaped articles by a variety of means as described below. In
particular aspects the article includes a thin wall including the
thermoplastic composition having a nominal thickness of less than
about 2 mm.
[0056] Articles formed from thermoplastic compositions according to
the present disclosure may include, but are not limited to: a
communication device; a computer device; an electromagnetic
interference device; a printed circuit; a Wi-Fi device; a Bluetooth
device; a GPS device; a cellular antenna device; a smart phone
device; a wireless communication device; a structured media
enclosure; an antenna concealing enclosure; an enclosure for
networking equipment (including routers, switches, hubs, modems and
servers); a structural component of an electronic device; a
portable computing device; a hand-held electronic device; an
automotive device; a medical device; a sensor device; a security
device; a shielding device; an RF antenna device; an LED device;
and an RFID device.
Methods for Making Articles Including the Thermoplastic
Compositions
[0057] Articles including the thermoplastic compositions according
to aspects described herein may be formed according to any
conventional method. In some aspects the article is
extrusion-molded, injection-molded, compression-molded,
thermoformed, overmolded, or insert-molded with a metallic or
composite laminate insert.
[0058] If extrusion-molded, the one or any foregoing components
described herein may first be dry blended together, then fed into
an extruder from one or multi-feeders, or separately fed into an
extruder from one or multi-feeders. The one or any foregoing
components may be first dry blended with each other, or dry blended
with any combination of foregoing components, then fed into an
extruder from one or multi-feeders, or separately fed into an
extruder from one or multi-feeders. The components may be fed into
the extruder from a throat hopper or any side feeders.
[0059] The extruders used in the invention may have a single screw,
multiple screws, intermeshing co-rotating or counter rotating
screws, non-intermeshing co-rotating or counter rotating screws,
reciprocating screws, conical screws, screws with pins, screws with
screens, barrels with pins, rolls, rams, helical rotors,
co-kneaders, disc-pack processors, various other types of extrusion
equipment, or combinations comprising at least one of the
foregoing.
[0060] The barrel temperature on the extruder during compounding
can be set at the temperature where at least a portion of the
thermoplastic polymer(s) in the thermoplastic composition have
reached a temperature greater than or equal to about the melting
temperature, if the thermoplastic polymer(s) is a semi-crystalline
organic polymer, or the flow point (e.g., the glass transition
temperature) if the thermoplastic polymer(s) is an amorphous
polymer.
[0061] The mixture including the foregoing mentioned components may
be subject to multiple blending and forming steps if desirable. For
example, the thermoplastic composition may first be extruded and
formed into pellets. The pellets may then be fed into a molding
machine where it may be formed into any desirable shape or product.
Alternatively, the thermoplastic composition emanating from a
single melt blender may be formed into sheets or strands and
subjected to post-extrusion processes such as annealing, uniaxial
or biaxial orientation.
[0062] In particular aspects in which the article is
extrusion-molded, a method for making a thermoplastic composition
includes: combining the components of the thermoplastic composition
to form a mixture; adding the mixture at a feed throat of an
extruder and compounding the mixture in the extruder; and extruding
the mixture into a mold to form the article. In other aspects one
or more of the components of the thermoplastic composition (e.g.,
the ceramic fiber component) may be added downstream in the
extruder according to conventional methods.
[0063] Various combinations of elements of this disclosure are
encompassed by this disclosure, e.g., combinations of elements from
dependent claims that depend upon the same independent claim.
Aspects of the Disclosure
[0064] In various aspects, the present disclosure pertains to and
includes at least the following aspects.
[0065] Aspect 1. A thermoplastic composition comprising, consisting
of, or consisting essentially of:
[0066] a. from about 29 wt % to about 49 wt % of a thermoplastic
polymer component comprising [0067] i. a first thermoplastic
polymer consisting of polybutylene terephthalate, and [0068] ii. a
second thermoplastic polymer consisting of polycarbonate,
polyethylene terephthalate, copolymers thereof, or a combination
thereof, [0069] wherein the first thermoplastic polymer is present
the composition in a ratio of at least 2:1 as compared to the
second thermoplastic polymer;
[0070] b. from about 1 wt % to about 30 wt % of a component
comprising a polyester elastomer, an ethylene/alkyl
acrylate/glycidyl methacrylate terpolymer compatibilizer, or a
combination thereof; and
[0071] c. from about 50 wt % to about 70 wt % of a ceramic fiber
component comprising ceramic fibers,
wherein the combined weight percent value of all components does
not exceed 100 wt %, and all weight percent values are based on the
total weight of the composition.
[0072] Aspect 2. The composition according to Aspect 1, wherein the
second thermoplastic polymer comprises polycarbonate and a
polycarbonate copolymer, wherein the polycarbonate is a homopolymer
comprising repeating units derived from bisphenol A, and wherein
the polycarbonate copolymer comprises repeating units derived from
bisphenol A, sebacic acid, polysiloxane, isophthalate terephthalate
resorcinol (ITR), phosphate or a combination thereof.
[0073] Aspect 3. The composition according to Aspect 2, wherein the
polycarbonate copolymer comprises a polycarbonate-polysiloxane
copolymer having a siloxane content of from about 5 wt % to about
45 wt % based on the total weight of the polycarbonate-polysiloxane
copolymer.
[0074] Aspect 4. The composition according to any of Aspects 1-3,
wherein the polycarbonate is a polycarbonate copolymer including
repeating units derived from bisphenol A, sebacic acid,
polysiloxane, isophthalate terephthalate resorcinol (ITR),
phosphate, or a combination thereof.
[0075] Aspect 5. The composition according to any of Aspects 1-4,
wherein the ceramic fibers have a tensile modulus of at least 150
GPa.
[0076] Aspect 6. The composition according to any of Aspects 1-5,
wherein the ceramic fibers have a tensile modulus of at least 300
GPa.
[0077] Aspect 7. The composition according to any of Aspects 1-6,
wherein the ceramic fibers comprise chopped ceramic fibers having a
length of from about 0.1 millimeter (mm) to about 1 mm in the
composition.
[0078] Aspect 8. The composition according to any of Aspects 1-7,
wherein the composition has a tensile modulus of at least 27 GPa as
determined in accordance with ASTM D638 or a notched Izod impact
strength greater than 280 Jim at 23.degree. C. as determined in
accordance with ASTM D256.
[0079] Aspect 9. The composition according to any of Aspects 1-8,
wherein the ceramic fiber component is a continuous laminate, a
unidirectional tape, or prepeg.
[0080] Aspect 10. The composition according to any of Aspects 1-9,
wherein the ceramic fibers comprise alumina.
[0081] Aspect 11. The composition according to any of Aspects 1-9,
wherein the ceramic fibers comprise an alpha-crystalline
alumina.
[0082] Aspect 12. The composition according to any of Aspects 1-11,
further comprising a crystallization suppressant in an amount of
from greater than 0 wt % to about 10 wt %.
[0083] Aspect 13. The composition according to any of Aspects 1-12,
further comprising a transesterification quenching agent in an
amount of from greater than 0 wt % to about 1 wt %.
[0084] Aspect 14. The composition according to any of Aspects 1-13,
further comprising an additive material, the additive material
selected from the group consisting of: an antioxidant; a colorant;
a de-molding agent; a dye; a flow promoter; a flow modifier; a
light stabilizer; a lubricant; a mold release agent; a pigment; a
quenching agent; a thermal stabilizer; an ultraviolet (UV)
absorbant; a UV reflectant; a UV stabilizer; an epoxy chain
extender; a flame retardant; and a combination thereof.
[0085] Aspect 15. The composition according to any of Aspects 1-14,
wherein a molded sample of the thermoplastic composition has a
tensile modulus of at least about 25 gigapascals (GPa) as
determined in accordance with ASTM D638.
[0086] Aspect 16. The composition according to any of Aspects 1-15,
wherein a molded sample of the thermoplastic composition has a
flexural modulus of at least about 15 GPa as determined in
accordance with ASTM D638.
[0087] Aspect 17. The composition according to any of Aspects 1-16,
wherein the thermoplastic composition is chemically resistant.
[0088] Aspect 18. The composition according to any of Aspects 1-17,
wherein the ceramic fibers are nonmagnetic or non-electrically
conductive.
[0089] Aspect 19. The composition according to any of Aspects 1-18,
wherein the composition has a flexural modulus as determined in
accordance with ASTM D638 that is at least about 50% higher than
that of a comparative composition that includes glass fibers
instead of the ceramic fiber component comprising ceramic
fibers.
[0090] Aspect 20. The composition according to any of Aspects 1-19,
wherein the composition has a tensile modulus as determined in
accordance with ASTM D638 that is at least about 50% higher than
that of a comparative composition that includes glass fibers
instead of the ceramic fiber component comprising ceramic
fibers.
[0091] Aspect 21. The composition according to any of Aspects 1-20,
wherein the composition has a melt volume rate (MVR) as tested
according to ASTM D1238 at 285.degree. C. and 5 kilograms that is
at least about 50% higher than that of a comparative composition
that includes glass fibers instead of the ceramic fiber component
comprising ceramic fibers.
[0092] Aspect 22. An article comprising a composition according to
any of Aspects 1-21, wherein the article comprises a thin wall
having a nominal thickness of less than about 2 mm.
[0093] Aspect 23. The article according to Aspect 22, wherein the
article has a shear viscosity at 150 cp of less than about 2500
s.sup.-1 as determined in accordance with ASTM D3835.
[0094] Aspect 24. The article according to Aspect 22 or 23, wherein
the article is extrusion-molded, injection-molded,
compression-molded, thermoformed, overmolded, or insert-molded with
a metallic or composite laminate insert.
[0095] Aspect 25. The article according to any of Aspects 22-24,
wherein the article is selected from the group consisting of: a
communication device; a computer device; an electromagnetic
interference device; a printed circuit; a Wi-Fi device; a Bluetooth
device; a GPS device; a cellular antenna device; a smart phone
device; a wireless communication device; a structured media
enclosure; an antenna concealing enclosure; an enclosure for
networking equipment; a structural component of an electronic
device; a portable computing device; a hand-held electronic device;
an automotive device; a medical device; a sensor device; a security
device; a shielding device; an RF antenna device; an LED device;
and an RFID device.
Definitions
[0096] It is also to be understood that the terminology used herein
is for the purpose of describing particular aspects only and is not
intended to be limiting. As used in the specification and in the
claims, the term "comprising" can include the embodiments
"consisting of" and "consisting essentially of." Unless defined
otherwise, all technical and scientific terms used herein have the
same meaning as commonly understood by one of ordinary skill in the
art to which this disclosure belongs. In this specification and in
the claims which follow, reference will be made to a number of
terms which shall be defined herein.
[0097] As used in the specification and the appended claims, the
singular forms "a," "an" and "the" include plural referents unless
the context clearly dictates otherwise. Thus, for example,
reference to "a polycarbonate" includes mixtures of two or more
polycarbonate polymers.
[0098] As used herein, the term "combination" is inclusive of
blends, mixtures, alloys, reaction products, and the like.
[0099] Ranges can be expressed herein as from one value (first
value) to another value (second value). When such a range is
expressed, the range includes in some aspects one or both of the
first value and the second value. Similarly, when values are
expressed as approximations, by use of the antecedent `about,` it
will be understood that the particular value forms another aspect.
It will be further understood that the endpoints of each of the
ranges are significant both in relation to the other endpoint, and
independently of the other endpoint. It is also understood that
there are a number of values disclosed herein, and that each value
is also herein disclosed as "about" that particular value in
addition to the value itself. For example, if the value "10" is
disclosed, then "about 10" is also disclosed. It is also understood
that each unit between two particular units are also disclosed. For
example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are
also disclosed.
[0100] As used herein, the terms "about" and "at or about" mean
that the amount or value in question can be the designated value,
approximately the designated value, or about the same as the
designated value. It is generally understood, as used herein, that
it is the nominal value indicated .+-.10% variation unless
otherwise indicated or inferred. The term is intended to convey
that similar values promote equivalent results or effects recited
in the claims. That is, it is understood that amounts, sizes,
formulations, parameters, and other quantities and characteristics
are not and need not be exact, but can be approximate and/or larger
or smaller, as desired, reflecting tolerances, conversion factors,
rounding off, measurement error and the like, and other factors
known to those of skill in the art. In general, an amount, size,
formulation, parameter or other quantity or characteristic is
"about" or "approximate" whether or not expressly stated to be
such. It is understood that where "about" is used before a
quantitative value, the parameter also includes the specific
quantitative value itself, unless specifically stated
otherwise.
[0101] As used herein, the terms "optional" or "optionally" means
that the subsequently described event or circumstance can or cannot
occur, and that the description includes instances where said event
or circumstance occurs and instances where it does not. For
example, the phrase "optional additive material" means that the
additive material can or cannot be included in the thermoplastic
composition and that the description includes thermoplastic
compositions that both include and do not include additive
materials.
[0102] Disclosed are the components to be used to prepare the
compositions of the disclosure as well as the compositions
themselves to be used within the methods disclosed herein. These
and other materials are disclosed herein, and it is understood that
when combinations, subsets, interactions, groups, etc. of these
materials are disclosed that while specific reference of each
various individual and collective combinations and permutation of
these compounds cannot be explicitly disclosed, each is
specifically contemplated and described herein. For example, if a
particular compound is disclosed and discussed and a number of
modifications that can be made to a number of molecules including
the compounds are discussed, specifically contemplated is each and
every combination and permutation of the compound and the
modifications that are possible unless specifically indicated to
the contrary. Thus, if a class of molecules A, B, and C are
disclosed as well as a class of molecules D, E, and F and an
example of a combination molecule, A-D is disclosed, then even if
each is not individually recited each is individually and
collectively contemplated meaning combinations, A-E, A-F, B-D, B-E,
B-F, C-D, C-E, and C-F are considered disclosed. Likewise, any
subset or combination of these is also disclosed. Thus, for
example, the sub-group of A-E, B-F, and C-E would be considered
disclosed. This concept applies to all aspects of this application
including, but not limited to, steps in methods of making and using
the compositions of the disclosure. Thus, if there are a variety of
additional steps that can be performed it is understood that each
of these additional steps can be performed with any specific aspect
or combination of aspects of the methods of the disclosure.
[0103] References in the specification and concluding claims to
parts by weight of a particular element or component in a
composition or article, denotes the weight relationship between the
element or component and any other elements or components in the
composition or article for which a part by weight is expressed.
Thus, in a compound containing 2 parts by weight of component X and
5 parts by weight component Y, X and Y are present at a weight
ratio of 2:5, and are present in such ratio regardless of whether
additional components are contained in the compound.
[0104] A weight percent of a component, unless specifically stated
to the contrary, is based on the total weight of the formulation or
composition in which the component is included.
[0105] The terms "BisA," "BPA," or "bisphenol A," which can be used
interchangeably, as used herein refers to a compound having a
structure represented by the formula:
##STR00001##
BisA can also be referred to by the name
4,4'-(propane-2,2-diyl)diphenol; p,p'-isopropylidenebisphenol; or
2,2-bis(4-hydroxyphenyl)propane. BisA has the CAS #80-05-7.
[0106] As used herein the terms "weight percent," "%," and "wt. %,"
which can be used interchangeably, indicate the percent by weight
of a given component based on the total weight of the composition,
unless otherwise specified. That is, unless otherwise specified,
all wt % values are based on the total weight of the composition.
It should be understood that the sum of wt % values for all
components in a disclosed composition or formulation are equal to
100.
[0107] Unless otherwise stated to the contrary herein, all test
standards are the most recent standard in effect at the time of
filing this application.
[0108] Each of the materials disclosed herein are either
commercially available and/or the methods for the production
thereof are known to those of skill in the art.
[0109] It is understood that the compositions disclosed herein have
certain functions. Disclosed herein are certain structural
requirements for performing the disclosed functions and it is
understood that there are a variety of structures that can perform
the same function that are related to the disclosed structures, and
that these structures will typically achieve the same result.
EXAMPLES
[0110] The following examples are put forth so as to provide those
of ordinary skill in the art with a complete disclosure and
description of how the compounds, compositions, articles, devices
and/or methods claimed herein are made and evaluated, and are
intended to be purely exemplary and are not intended to limit the
disclosure. Efforts have been made to ensure accuracy with respect
to numbers (e.g., amounts, temperature, etc.), but some errors and
deviations should be accounted for. Unless indicated otherwise,
parts are parts by weight, temperature is in .degree. C. or is at
ambient temperature, and pressure is at or near atmospheric. Unless
indicated otherwise, percentages referring to composition are in
terms of wt %.
[0111] There are numerous variations and combinations of reaction
conditions, e.g., component concentrations, desired solvents,
solvent mixtures, temperatures, pressures and other reaction ranges
and conditions that can be used to optimize the product purity and
yield obtained from the described process. Only reasonable and
routine experimentation will be required to optimize such process
conditions.
[0112] Table 1 provides a list of components used in one or more of
the comparative and example compositions described herein:
TABLE-US-00001 TABLE 1 Components Component Source Description
VALOX .TM. 315 PBT SABIC High MW, virgin PBT VALOX .TM. 195 PBT
SABIC Low MW, virgin PBT PBT LOW IV IQ SABIC Low MW PBT LEXAN .TM.
104 PC SABIC Polycarbonate (PC) ML7698 PC copolymer SABIC
PC-Siloxane copolymer (40% siloxane content in copolymer) C9030P PC
copolymer SABIC PC-Siloxane copolymer (20% siloxane content in
copolymer) SLX PC copolymer 90/10 SABIC Polycarbonate copolymer
resin, crystallization suppressant HFD1810 PC copolymer SABIC High
flow ductile PC copolymer Lotader .RTM. AX8900 Arkema
Ethylene/acrylic ester/glycidyl methacrylate terpolymer terpolymer,
impact modifier Hytrel .RTM. 4056 PE DuPont Polyester elastomer,
impact modifier elastomer Elvaloy AC .RTM. copolymer DuPont
Ethylene-ethylacrylate copolymer, impact modifier Irganox .RTM.
1010 BASF Antioxidant EVERFOS .RTM. 168 Everspring Processing
stabilizer TINUVIN .RTM. 329 BASF Ultraviolet absorber MZP ICL Mono
zinc phosphate, catalyst quencher GLYCOLUBE PETS Lonza
Pentaerythritol tetrastearate (PETS), mold release Carbon Black
Cabot Colorant Nextel .TM. 610 fiber 3M .alpha.-crystalline Al2O3
ceramic fiber
[0113] Comparative and example compositions were prepared and shown
in Tables 2A and 2B. Comparative composition C1 is based on a
composition previously developed for a 2.0 to 3.0 mm thick
enclosure/housing for a consumer electronic device. Example
composition Ex1 included only a lower MW PBT rather than the
combination of PBTs using in C1. Compositions Ex2-Ex4 included
different types of PC copolymers. Compositions Ex5-Ex7 included SLX
copolymer. Compositions Ex8 and Ex9 included PBT formed from
SABIC's IQ process, and have comparable loading levels to Ex5 and
Ex6. Composition Ex10 is an optimized composition based on the
observed properties of C1 and Ex1-Ex9.
TABLE-US-00002 TABLE 2A Component C1 Ex1 Ex2 Ex3 Ex4 VALOX .TM. 315
PBT 4.377 VALOX .TM. 195 PBT 16.964 21.341 21.341 21.341 21.341
LEXAN .TM. 104 PC 7.309 7.309 ML7698 7.309 C9030P PC-Si Copol 7.309
20% SLX PC 90/10 HFD1810 PC 7.309 Lotader .RTM. AX8900 6 6 6 6 6
Hytrel .RTM. 4056 2.5 2.5 2.5 2.5 2.5 Elvaloy AC .RTM. 2 2 2 2 2
Irganox .RTM. 1010 0.1 0.1 0.1 0.1 0.1 EVERFOS .RTM. 168 0.2 0.2
0.2 0.2 0.2 TINUVIN .RTM. 329 0.25 0.25 0.25 0.25 0.25 MZP 0.1 0.1
0.1 0.1 0.1 GLYCOLUBE PETS 0.2 0.2 0.2 0.2 0.2 Nextel .TM. 610 60
60 60 60 60 Total (wt %): 100.0 100.0 100.0 100.0 100.0
TABLE-US-00003 TABLE 2B Component Ex5 Ex6 Ex7 Ex8 Ex9 Ex10 VALOX
.TM. 195 PBT 44.35 35.31 24 PBT LOW IV IQ 44.05 35.02 19.307 ML7698
2 SLX PC 90/10 14.5 11.54 7.85 14.5 11.53 HFD1810 PC 7.309 Lotader
.RTM. AX8900 3 3 3 3 3 5 Hytrel .RTM. 4056 2.5 2.5 2.5 2.5 2.5 2.5
Elvaloy AC .RTM. 2 2 2 2 2 2 Irganox .RTM. 1010 0.1 0.1 0.1 0.1 0.1
0.1 EVERFOS .RTM. 168 0.2 0.2 0.2 TINUVIN .RTM. 329 0.25 0.25 0.25
0.25 0.25 0.25 MZP 0.1 0.1 0.1 0.2 0.2 0.1 GLYCOLUBE PETS 0.2 0.2
0.2 0.2 0.2 0.2 Nextel .TM. 610 33 45 60 33 45 60 Carbon Black
1.034 Total (wt %): 100.0 100.0 100.0 100.0 100.0 100.0
[0114] Various properties of the compositions shown above were
determined; results are shown in Tables 3A and 3B:
TABLE-US-00004 TABLE 3A Property Unit C1 Ex1 Ex2 Ex3 Ex4 Tensile
test, ASTM D 638, 5.08 mm/min, 23.degree. C. Modulus of
Elasticity-Avg MPa 30220 29900 27340 28300 29380 Tensile Strength
at Yield-Avg MPa 111 112 91.2 102 110 Tensile Strength at Break-Avg
MPa 109 111 88.2 93.4 108 % Elongation at Break-Avg % 2.83 2.46
3.64 3.22 2.64 Flexural test - ASTM D790, 3.2 mm, 1.4 mm/min
Flexural Modulus-Avg MPa 18379 191360 16073 17906 19098 Flexural
Stress@Yield-Avg MPa 173.1 176.1 143.1 162.2 177.1 Flexural
Stress@Break-Avg MPa 172.8 176.1 142.9 161.8 177.0 Notched IZOD
Impact Strength, J/m 293 284 317 312 300 ASTM D256, 23.degree. C.
Unnotched IZOD Impact Strength, J/m 1100 911 1040 1150 1040 ASTM
D256, 23.degree. C. Melt Volume-flow Rate (MVR), ASTM D1238, 5 kg,
360 s dwell 250.degree. C. 275.degree. C. NM NM NM NM NM
285.degree. C. 300.degree. C. 9.1 11.2 19.9 13.0 13.4
TABLE-US-00005 TABLE 3B Property Unit Ex5 Ex6 Ex7 Ex8 Ex9 Ex10
Tensile test, ASTM D 638, 5.08 mm/min, 23.degree. C. Modulus of
Elasticity-Avg MPa 17500 21960 29400 16760 22040 27920 Tensile
Strength at Yield- MPa 110 117 113 104 117 110 Avg Tensile Strength
at Break- MPa 108 116 112 104 116 109 Avg % Elongation at Break- %
1.71 1.47 1.24 1.68 1.81 2.7 Avg Flexural test - ASTM D790, 3.2 mm,
1.4 mm/min Flexural Modulus-Avg MPa 12609 15539 20770 12593 15860
19223 Flexural Stress@Yield- MPa 167.3 174.9 169.9 163.1 176.0
167.62 Avg Flexural Stress@Break- MPa 167.3 175.0 169.9 163.1 176.0
167.51 Avg Notched IZOD Impact J 101 129 164 107 143 252 Strength,
ASTM D256, 23.degree. C. Unnotched IZOD Impact J/m 633 731 609 685
810 882 Strength, ASTM D256, 23.degree. C. Melt Volume-flow Rate
(MVR), ASTM D1238, 5 kg, 360 s dwell 250.degree. C. 27.2 15.5 4.5
39.9 24.3 275.degree. C. 47.8 27.8 8.1 91.8 55.6 285.degree. C.
14.2 300.degree. C. 30.0
[0115] Units and abbreviations used in the tables and figures
include: millimeter per minute (mm/min); degrees Celsius (.degree.
C.); average (Avg); kilogram (kg); seconds (s); megapascal (MPa);
joule per meter (J/m); not measurable (NM); pascal-seconds (Pa-s);
and inverse seconds (1/s).
[0116] Comparative composition C1 and example compositions Ex1-Ex4
had a high tensile modulus (greater than 27 GPa) and very good
impact properties (notched Izod impact strength greater than 280
J/m). They did not, however, have good melt properties as observed
in the MVR data and the shear viscosity curves in FIG. 1. As a
result, it was difficult to mold thin plaques from these
compositions, and in fact when it was attempted to mold a 0.6 mm
thick plaque from composition C1, the highest possible pressure and
injection speed had to be used, resulting in damage to both the
nozzle and the bushing of the injection molding
machine/equipment/system.
[0117] Example compositions Ex5-Ex9 had a comparatively higher melt
flow (MVR), although it decreased sharply as fiber loading was
increased (compare MVR of Ex5 to Ex6 and then Ex7). These
compositions included the SLX PC copolymer resin, which functions
as a crystallization suppressant to slows down recrystallization of
the PBT resin. As a result, injection molded parts formed from
these compositions exhibited a smooth and shiny surface. These
compositions, however, do not have good impact and elongation
properties. In particular, Ex7 having a ceramic fiber content of 60
wt % had a notched Izod impact strength less than 180 J/m and an
elongation of less than 1.3%.
[0118] Example composition Ex8 and Ex9, including PBT resin formed
from SABIC's iQ process, generally had good mechanical properties
(mechanical, impact), surface quality and excellent melt flow (MVR)
as compared to using virgin PBT resin having a similar MW (see Ex5
and Ex6). Without being bound by theory, it is thought that since
the PBT formed from this process is from chemically recycled
sources, the polymer molecular chain structure and end groups could
be slightly different and as a result favor improved melt flow and
slower crystallization. In view of the results, the Ex8 and Ex9
compositions may be particularly suited for injection molding
thin-wall structures.
[0119] Rheology analysis: for fiber reinforced composites, in
particular those having a high fiber loading, capillary shear
viscosity is more accurate and meaningful for guiding the molding
process the melt flow volume rate (MVR). Shear viscosity for the
compositions is illustrated in FIGS. 1-3. Shear viscosity was
determined according to ASTM D3835 at 285.degree. C. (C1, Ex1-Ex4),
275.degree. C. (Ex5-Ex9) and 285.degree. C. (Ex10). Polymer or
polymeric composite melts exhibit shear thinning behavior; that is,
the higher shear rate, the lower viscosity. For molding a thin-wall
structure, it is common to increase the injection molding speed to
increase the shear rate in order to lower the melt viscosity for
mold filling. However, a very high injection speed can be achieved
by applying a very high injection molding pressure, which is
challenging for an injection molding equipment. In addition,
unwanted residual stress may exist in the molded parts, causing
premature failure (e.g. cracking), warpage and dimensional
instability and poor surface quality (e.g., residual flow marks on
the part surface).
[0120] For thinner wall structures, lower viscosity at a lower
shear rate may be particularly desirable. It is found that the
shear viscosity at 150 cp should in some aspects be less than about
4,000 s.sup.-1 when molding for a thin-wall structure at the
thickness of 0.6 mm.
[0121] With reference to FIG. 1, when injection molding a thin
plaque at the dimension of 0.6 mm.times.60 mm.times.60 mm,
composition C1--which had a shear viscosity of at 127 cp of about
4000 s.sup.-1 or about 3200 s.sup.-1 at 150 cp--was very difficult
to fill into the mold, and as noted above the injection molding
equipment was damaged. In contrast, the compositions including all
lower molecular weight PBT (Ex1) or modified by HFD resin (Ex4) had
a much lower viscosity (about 2300 s.sup.-1 at 150 cp). When the
PC-siloxane copolymers were used (Ex2 and Ex3), the viscosity
dropped significantly further (less than about 2000 s.sup.-1 at 150
cp), making thin-wall molding feasible.
[0122] FIG. 2 shows the compositions including ceramic fiber at a
range of fiber loading levels, and including a crystallization
suppressant. As shown, the melt viscosity of these compositions was
reduced (less than 2400 s.sup.-1 at 150 cp). Comparing Ex5, Ex6 and
Ex7, melt viscosity increases dramatically when fiber loading level
increases from 33 wt % to 45 wt % and then 60 wt %. This indicates
that when fiber loading is high, melt flow decreases. Comparing the
viscosity of composition Ex5 to Ex8 at 33 wt % fiber loading,
compositions Ex6 and Ex9 at 45 wt % fiber loading, and Ex7 to Ex10
at 60 wt % fiber loading, the compositions including the iQ-PBT
(Ex8, Ex9 and Ex10) had a significantly lower viscosity than their
comparative compositions (Ex5, Ex6 and Ex7) that included virgin
PBT resin. These observations were consistent with the MVR data for
these compositions.
[0123] Further, as shown in FIG. 3, Ex10--the high-stiff fiber
composite--had a much lower viscosity compared to the other
compositions including 60 wt % ceramic fiber (C1, Ex1-Ex4, and
Ex7). In addition, the lower viscosity of Ex10 (150 cp at 1250
s.sup.-1), is achieved by formulation optimization and utilizing
SABIC proprietary PC copolymer technology. The Ex10 composition
also exhibited excellent impact properties (252 Jim notched Izod
impact strength and 2.7% elongation at break).
[0124] Additional example and comparative compositions were made
and tested to evaluate the differences between including ceramic
fiber in compositions according to aspects of the disclosure (Ex11
and Ex12) as compared to compositions including conventional glass
fiber (C11 and C12). The compositions are shown in Table 4A:
TABLE-US-00006 TABLE 4A Ex11 C11 Ex12 C12 VALOX .TM. 315 PBT %
5.377 5.377 7.076 7.076 VALOX .TM. 195 PBT % 17.69 17.69 24.311
24.311 Lotader .RTM. AX8900 % 3 3 3 3 Hytrel .RTM. 4056 % 2.5 2.5
2.5 2.5 Glycolube PETS % 0.2 0.2 0.2 0.2 Irganox .RTM. 1010 % 0.1
0.1 0.1 0.1 EVERFOS .RTM. 168 % 0.2 0.2 0.2 0.2 MZP % 0.1 0.1 0.1
0.1 TINUVIN .RTM. 329 % 0.25 0.25 0.25 0.25 Elvaloy AC .RTM. % 2 2
2 2 Lexan .TM. 104 (Homopolymer PC) % 7.549 7.549 10.263 10.263
Carbon black % 1.034 1.034 Nextel .TM. 610 % 60 50 Johns Manville
JM 718 (E-Glass fiber) % 60 Nitto Boseki CSG 3PA-830 (flat E-GF) %
50 Total (%) 100 100 100 100
[0125] Lexan.TM. 104 is a polycarbonate homopolymer from SABIC
having a melt volume rate (MVR) of 7 cubic centimeters
(cm.sup.3)/10 minutes at 300.degree. C. and 1.2 kilograms. The JM
718 E-glass fiber is a round glass fiber having a diameter of about
10 micron and a pre-compounded length of about 4 millimeters (mm).
The 3PA-830 glass fiber is a chopped, oval-shaped E-glass fiber
with a modification ratio of 4 (width of 28 micron to thickness of
7 micron) and an average chopped fiber length of 3 mm. The
compositions of Table 4A were tested and are shown in Table 4B:
TABLE-US-00007 TABLE 4B Ex11 C11 Ex12 C12 Specific Gravity 2.009
1.775 1.832 1.6645 Flexural Modulus GPa 22.6 15.4 19.7 12.7
Flexural Stress@Yield MPa 158 188 184 257 Flexural Stress@Break MPa
139 160 184 256 Notched Izod Impact Strength J/m 128 160 154 229
Unnotched Izod Impact J/m 694 727 691 1100 Strength Tensile Modulus
GPa 30.24 18.92 26.38 15.98 Tensile Strength at Yield MPa 103 127
120 173 Tensile Strength at Break MPa 102 126 120 173 % Elongation
at Yield % 1.3 1.85 1.47 2.08 % Elongation at Break % 1.43 1.9 1.54
2.11 MVR (275 C., 5 Kg) cm.sup.3/10 25.1 * 26.4 15 min MVR (285 C.,
5 Kg) cm.sup.3/10 38.7 2.84 45.1 25 min
[0126] Ex 11 and Ex 12 and their corresponding comparative
compositions include two PBT components and polycarbonate
homopolymer as the second thermoplastic polymer. The compatibilizer
is Lotader.RTM. AX8900. From the data in Table 4B it is observed
that compositions including ceramic fiber had a substantially
higher stiffness (flexural modulus and tensile modulus) and a much
higher melt flow (MVR) as compared to the comparative compositions
that include glass fiber.
[0127] From the collective data it is observed that the
compositions according to aspects of the disclosure have improved
processability without compromising their mechanical
properties.
[0128] The above description is intended to be illustrative, and
not restrictive. For example, the above-described examples (or one
or more aspects thereof) may be used in combination with each
other. Other embodiments can be used, such as by one of ordinary
skill in the art upon reviewing the above description. The Abstract
is provided to allow the reader to quickly ascertain the nature of
the technical disclosure. It is submitted with the understanding
that it will not be used to interpret or limit the scope or meaning
of the claims. Also, in the above Detailed Description, various
features may be grouped together to streamline the disclosure. This
should not be interpreted as intending that an unclaimed disclosed
feature is essential to any claim. Rather, inventive subject matter
may lie in less than all features of a particular disclosed
embodiment. Thus, the following claims are hereby incorporated into
the Detailed Description as examples or embodiments, with each
claim standing on its own as a separate embodiment, and it is
contemplated that such embodiments can be combined with each other
in various combinations or permutations. The scope of the invention
should be determined with reference to the appended claims, along
with the full scope of equivalents to which such claims are
entitled.
* * * * *